<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Define a color as transparent</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagecolorstotal.html">imagecolorstotal</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imageconvolution.html">imageconvolution</a></div> <div class="up"><a href="ref.image.html">GD and Image Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="function.imagecolortransparent" class="refentry"> <div class="refnamediv"> <h1 class="refname">imagecolortransparent</h1> <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">imagecolortransparent</span> — <span class="dc-title">Define a color as transparent</span></p> </div> <div class="refsect1 description" id="refsect1-function.imagecolortransparent-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">int</span> <span class="methodname"><strong>imagecolortransparent</strong></span> ( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$image</code></span> [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$color</code></span> ] )</div> <p class="para rdfs-comment"> Sets the transparent color in the given <em><code class="parameter">image</code></em>. </p> </div> <div class="refsect1 parameters" id="refsect1-function.imagecolortransparent-parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><em><code class="parameter"> image</code></em></span><dd> <p class="para">An image resource, returned by one of the image creation functions, such as <span class="function"><a href="function.imagecreatetruecolor.html" class="function">imagecreatetruecolor()</a></span>.</p></dd> </dt> <dt> <span class="term"><em><code class="parameter">color</code></em></span> <dd> <p class="para"> A color identifier created with <span class="function"><a href="function.imagecolorallocate.html" class="function">imagecolorallocate()</a></span>. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues" id="refsect1-function.imagecolortransparent-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> The identifier of the new (or current, if none is specified) transparent color is returned. If <em><code class="parameter">color</code></em> is not specified, and the image has no transparent color, the returned identifier will be -1. </p> </div> <div class="refsect1 examples" id="refsect1-function.imagecolortransparent-examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example" id="example-3199"> <p><strong>Example #1 <span class="function"><strong>imagecolortransparent()</strong></span> example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// Create a 55x30 image<br /></span><span style="color: #0000BB">$im </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecreatetruecolor</span><span style="color: #007700">(</span><span style="color: #0000BB">55</span><span style="color: #007700">, </span><span style="color: #0000BB">30</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$red </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecolorallocate</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$black </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecolorallocate</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Make the background transparent<br /></span><span style="color: #0000BB">imagecolortransparent</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">$black</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Draw a red rectangle<br /></span><span style="color: #0000BB">imagefilledrectangle</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">4</span><span style="color: #007700">, </span><span style="color: #0000BB">4</span><span style="color: #007700">, </span><span style="color: #0000BB">50</span><span style="color: #007700">, </span><span style="color: #0000BB">25</span><span style="color: #007700">, </span><span style="color: #0000BB">$red</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Save the image<br /></span><span style="color: #0000BB">imagepng</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #DD0000">'./imagecolortransparent.png'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagedestroy</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> <div class="example-contents"><p>The above example will output something similar to:</p></div> <div class="mediaobject"> <div class="imageobject"> <img src="images/21009b70229598c6a80eef8b45bf282b-imagecolortransparent.png" alt="Output of example : imagecolortransparent()" width="55" height="30" /> </div> </div> </div> </p> </div> <div class="refsect1 notes" id="refsect1-function.imagecolortransparent-notes"> <h3 class="title">Notes</h3> <blockquote class="note"><p><strong class="note">Note</strong>: <p class="para"> Transparency is copied only with <span class="function"><a href="function.imagecopymerge.html" class="function">imagecopymerge()</a></span> and true color images, not with <span class="function"><a href="function.imagecopy.html" class="function">imagecopy()</a></span> or pallete images. </p> </p></blockquote> <blockquote class="note"><p><strong class="note">Note</strong>: <p class="para"> The transparent color is a property of the image, transparency is not a property of the color. Once you have set a color to be the transparent color, any regions of the image in that color that were drawn previously will be transparent. </p> </p></blockquote> </div> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagecolorstotal.html">imagecolorstotal</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imageconvolution.html">imageconvolution</a></div> <div class="up"><a href="ref.image.html">GD and Image Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>